Refrigerating meat paste

Abstract

In a process for refrigerating protein materials, the material is prepared as a viscous paste at a relatively hot temperature and applied to a refrigerated heat transfer surface on a rotating drum, the temperatures of the protein material and the drum surface having a predetermined differential to cause congealed or frozen liquid at the interface between the protein material and drum surface to initially melt and immediately thereafter congeal or freeze in order to cause adhesion of the protein material to the surface. The protein material is compressed against the drum surface to improve heat transfer characteristics and subsequently removed in a suitably refrigerated or frozen condition. Initial heating may be extended to render excessive fat or to reduce bacterial content. Opposite surfaces of the sheet of material may also be contacted by first and second refrigerated heat transfer surfaces either simultaneously or in successive order. The temperature of an application roller for applying the viscous paste to the drum surface is preferably controlled to prevent sticking of the material to the application roller.

What is claimed is: 
     
       1. In a refrigeration process adapted for processing protein-containing solid food materials comprising meat products subject to rapid undesirable bacterial growth, the steps comprising forming the protein-containing solid food material into a viscous paste,   refrigerating a cylindrical heat transfer surface of a rotating drum to a temperature at or below freezing,   applying the viscous paste onto the heat transfer surface of the rotating drum to form a sheet of viscous paste on the heat transfer surface, the relative temperatures of the viscous paste and the heat transfer surface being selected so that, upon application of the viscous paste to the heat transfer surface, the relatively high temperature viscous paste is capable of momentarily melting or liquefying congealed or frozen liquid initially present along an interface between the heat transfer surface and the sheet of viscous paste material, the relatively low temperature heat transfer surface thereafter causing the liquid components at the interface to form a congealed or frozen solid in order to cause adhesion of the viscous paste to the heat transfer surface,   compressing the sheet in order to improve the heat transfer characteristics across its thickness,   cooling the viscous paste upon the heat transfer surface during rotation of the drum, and   subsequently removing the viscous paste from the heat transfer surface in a frozen condition.   
     
     
       2. The process of claim 1 wherein the paste material is a fat-containing animal product and is initially heated to a rendering temperature and maintained at that temperature in order to remove excess fat content prior to applying the viscous paste onto the heat transfer surface at said preselected relatively high temperature. 
     
     
       3. The process of claim 1 wherein the viscous paste is initially heated to a temperature selected for reducing its bacterial content and subsequently applying the viscous paste onto the heat transfer surface at said preselected relatively high temperature. 
     
     
       4. The process of claim 1 further comprising the additional step of also cooling the external surface of the sheet of viscous paste upon the heat transfer surface in order to decrease the time period required for refrigerating the viscous paste. 
     
     
       5. The process of claim 4 wherein the additional step of refrigerating the external surface of the sheet of viscous paste is performed simultaneously while the viscous paste is in engagement with the heat transfer surface. 
     
     
       6. The process of claim 1 further comprising the step of removing the viscous paste sheet from the heat transfer surface before the external surface of the viscous paste sheet is totally refrigerated, applying the sheet of viscous paste to a second refrigerated surface means arranged for contact with the external surface of the viscous paste sheet, and subsequently removing the viscous paste sheet from the second refrigerated surface means after the viscous paste sheet is frozen. 
     
     
       7. The process of claim 6 further comprising the additional step of initially establishing a temperature differential between the external surface of the viscous paste sheet and the second refrigerated surface means to cause adhesion of the viscous paste sheet thereto. 
     
     
       8. The process of claim 1 being further adapted for processing pork and other meat products which may be subject to trichinosis wherein the heat transfer surface is maintained at a temperature selected to assure destruction of trichinosis bacteria and the viscous paste remains in contact with the heat transfer surface for a period of time selected to insure that the paste is uniformly refrigerated to or below said selected temperature. 
     
     
       9. The process of claim 1 further comprising the step of compressing the viscous paste against the heat transfer surface after application of the viscous paste thereto in order to maintain heat transfer characteristics across the thickness of the viscous paste. 
     
     
       10. The process of claim 9 wherein said protein-containing material includes meat and vegetable components. 
     
     
       11. The process of claim 1 wherein said protein-containing material includes meat and vegetable components. 
     
     
       12. The process of claim 1 further comprising the step of dividing the viscous paste into patties. 
     
     
       13. The process of claim 1 further comprising the step of dividing the viscous paste into patties. 
     
     
       14. The process of claim 13 wherein the viscous paste is divided into patties after being removed from the heat transfer surface. 
     
     
       15. In a refrigeration process adapted for processing protein-containing solid food material comprising meat products subject to rapid and undesirable bacterial growth, the steps comprising, forming the protein-containing material into a viscous paste,   refrigerating a cylindrical heat transfer surface of a rotating drum to a preselected temperature,   applying the viscous paste onto the cylindrical heat transfer surface of the rotating drum to form a sheet of the viscous paste upon the cylindrical heat transfer surface, the viscous paste and heat transfer surface initially having a relatively high temperature and a relatively low temperature, the relative temperatures being selected so that, upon application of the viscous paste to the heat transfer surface, the relatively high temperature of the viscous paste is capable of initially melting congealed or frozen liquid at an interface between the viscous paste and the heat transfer surface, the relatively low temperature of the heat transfer surface immediately thereafter causing liquid components at the interface to form a congealed or frozen solid in order to cause adhesion of the viscous paste to the heat transfer surface,   compressing the sheet in order to improve heat transfer characteristics across its thickness,   cooling the viscous paste upon the heat transfer surface,   removing the sheet of viscous paste from the heat transfer surface and transferring it to a heat transfer surface of a second refrigerated rotating drum, the temperature differential between said second heat transfer drum surface and the viscous paste being selected to promote adhesion of the viscous paste to the second heat transfer drum surface,   cooling the viscous paste upon the second heat transfer drum surface, and   subsequently removing the viscous paste from the second heat transfer drum surface in frozen condition.   
     
     
       16. The process of claim 15 further comprising the step of compressing the viscous paste against both the heat transfer surface and said second heat transfer drum surface in order to improve heat transfer characteristics throughout the thickness of the viscous paste. 
     
     
       17. In a process for treating a protein-containing meat product having a high fat content in order to first recover a substantial portion of the fat and then refrigerate remaining protein-containing solids in order to limit bacterial growth, the steps comprising, heating the meat product in order to render and separate a substantial portion of the fat from the remaining protein-containing solid material,   forming the remaining solid material into a viscous paste,   refrigerating a cylindrical heat transfer surface of a rotating drum to a preselected temperature,   applying the viscous paste onto the heat transfer surface to form a sheet of the viscous paste on the heat transfer surface, the relatively high temperature of the viscous paste and the relatively low temperature of the heat transfer surface being selected so that, upon application of the viscous paste to the heat transfer surface, the relatively high temperature of the viscous paste is capable of causing congealed or frozen liquid at an interface between the heat transfer surface and the viscous paste to initially melt, the relatively low temperature of the heat transfer surface immediately thereafter causing liquid components at the interface to form a congealed or frozen solid in order to cause adhesion of the viscous paste to the heat transfer surface, compressing the viscous paste sheet in order to improve heat transfer characteristics throughout its thickness,   cooling the viscous paste upon the heat transfer surface of the rotating drum, and   subsequently removing the viscous paste from the heat transfer surface in a frozen condition.   
     
     
       18. In a process for treating meat products in order to first reduce the bacterial content of the product and then to rapidly refrigerate the meat product in order to limit further bacterial growth, the steps comprising, heating the meat product to a selected relatively high temperature in order to reduce the bacterial count thereof,   forming the meat product into a viscous paste,   refrigerating a cylindrical heat transfer surface of a rotating drum to a preselected temperature,   applying the viscous paste onto the heat transfer surface to form a sheet of the viscous paste upon the heat transfer surface, the viscous paste having a relatively high temperature and the heat transfer surface having a relatively low temperature upon application of the viscous paste to the heat transfer surface, the temperature of the paste and surface being selected so that the relatively hot temperature of the viscous paste is capable of causing congealed or frozen liquid at the interface between the viscous paste and the heat transfer surface to initially melt, the relatively low temperature of the heat transfer surface immediately thereafter causing liquid components at the interface to form a congealed or frozen solid in order to cause adhesion of the viscous paste to the heat transfer surface,   compressing the viscous paste sheet in order to improve heat transfer characteristics throughout its thickness,   cooling the viscous paste upon the heat transfer surface of the rotating drum, and   subsequently removing the viscous paste from the heat transfer surface of the rotating drum in a frozen condition.   
     
     
       19. In a refrigeration process adapted for processing protein-containing solid food material comprising meat products subject to rapid undesirable bacterial growth, the steps comprising forming the protein-containing solid food material into a viscous paste,   refrigerating a cylindrical heat transfer surface of a rotating drum to a temperature at or below freezing,   applying the viscous paste onto the heat transfer surface of the rotating drum by means of a rotatable feed drum arranged adjacent the rotating drum in order to form a sheet of viscous paste on the heat transfer surface, the relative temperature of the viscous paste and the heat transfer surface being selected so that, upon application of the viscous paste to the heat transfer surface, the sheet of viscous paste material is caused to adhere to the heat transfer surface,   compressing the viscous paste sheet in order to improve heat transfer characteristics throughout its thickness,   regulating the temperature of the feed drum at a temperature selected to facilitate release of the sheet of viscous material therefrom,   cooling the viscous paste upon the heat transfer surface during rotation of the drum, and   subsequently removing the viscous paste from the heat transfer surface in a frozen condition.